Washington D.C. [USA], Feb. 9 : Dear parents, if you want your three-year-old kid to learn and retain new words, then let them take a nap within an hour of learning the verbs.
According to researchers from University of Arizona in the US, the children who napped within an hour of learning the verbs performed better than those who stayed awake for at least five hours after learning, regardless of whether they were habitual nappers when tested 24 hours later.
The findings, published in the journal Child Development, suggests that parents may want to consider maintaining regular naptimes for preschoolers, who are at an age at which naps have a tendency to dwindle, said lead study author Michelle Sandoval.
The team tested 39 typically developing three-year-olds and divided them into two groups - habitual nappers (those who nap four or more days a week) and non-habitual nappers (those who nap three or fewer days per week).
Within each group, children were randomly assigned to either a napping condition, in which they would nap for at least 30 minutes after learning a new verb, or a wakefulness condition, in which they would not nap after learning.
They taught the children two made-up verbs -- "blicking" and "rooping" -- and showed them a video in which two different actors performed separately.
Twenty-four hours later, the children were shown videos of two new actors performing the same actions that they learned on the previous day and were asked which person was "blicking" and which was "rooping." "Regardless of typical napping behaviour, children who were in the sleep condition -- who were asked to nap after learning -- were the ones who generalised, and those who stayed awake were not able to generalise 24 hours later," Sandova explained.
"What's really important about this phase is that essentially what the brain is doing is replaying memories during sleep, so those brain rhythms that occur during slow-wave sleep and other phases of non-REM sleep are actually reactivating those patterns -- those memories -- and replaying them and strengthening them," explained study co-author Rebecca Gomez.